1. Field of the Invention
The present invention relates to optical devices in general, and more particularly, to the linking of a wireless hand held optical reader with a base unit or other wireless device.
2. Technical Background
In various commercial and industrial environments, the use of optical indicia, such as bar code symbols, has become the norm for identifying products and inventory. Typically, each item is marked with optical indicia associated with a description of the item and other attributes (for example, price) that are stored in a database of a host device or network system. Optical readers are used to read the optical indicia and provide that reading as input information to host devices. In some cases, the data is provided to the host devices via base units, which communicate with the optical reader. Examples of host devices include a computer (fixed or portable), a personal digital assistant (PDA), a portable data terminal (PDT), a point of sale (POS) terminal, a transaction terminal, cash register, or similar device. Checkout stations in retail settings typically employ stationary presentation-type optical readers, mobile hand held optical readers hardwired to a base unit, mobile wireless hand held optical readers that communicate wirelessly with a linked base unit, or some combination of the above to read optical indicia such as bar code symbols, or bar codes.
Stationary presentation-type optical readers, such as flat bed scanners, typically require a cashier to manually move an item bearing optical indicia into the field of view of the optical reader and orient the item such that the optical reader can scan the information and communicate this information to the cash register. While stationary presentation-type optical readers may be adequate for scanning encoded optical indicia on small items that are easily moved through their field of view by a cashier or other operator, these types of optical readers are not well suited for scanning large or heavy items that need to be repositioned by the cashier or customer so the scanner can read the optical indicia. This movement of large and/or heavy objects is inherently risky and undesirable. Furthermore, since stationary presentation-type optical readers require that the cashier position the item to be scanned somewhat precisely into the field of view of the optical reader so that the optical reader can scan the optical indicia, multiple attempts are often required to achieve a successful scan. This can lead to frustration by the cashier and customer and thus detract from customer satisfaction.
An advance upon the stationary presentation-type optical scanner is the use of a mobile hand held optical reader hardwired to a linked base unit. This configuration permits the cashier to manually move the hand held optical reader into position to scan an item's optical indicia, rather than having to move the item into the field of view of the optical reader as in the stationary presentation-type optical scanner. The scanned information from the optical indicia is then transmitted to the hand held optical reader's linked base unit via the hardwired connection between the two components. The base unit then communicates this information to the cash register. Alternatively, the hand held optical reader can be connected directly to the cash register. Unfortunately, this approach does not eliminate the problems associated with scanning items that are out of reach of the hardwired hand held optical reader and must be repositioned into the field of view of the optical reader so that the optical reader can scan the optical indicia.
In order to eliminate the limitations imposed by hardwiring the hand held optical reader to its base unit, another proposed approach is the use of a wireless optical reader that can communicate wirelessly with its linked base unit. In this approach, the wireless hand held optical reader is held in a base unit or docking cradle until needed to read optical indicia that are out of the view of a stationary presentation-type optical reader. The cashier can manually move the hand held optical reader into position to scan an item's optical indicia as long as the optical reader is within a distance where it can communicate wirelessly with its linked base unit. The scanned information is then transmitted to the hand held optical reader's linked base unit over the wireless connection. The base unit then communicates this bar code information to the cash register.
In the case of a mobile hand held optical reader hardwired to its individual base unit, this link between the reader and base unit is fixed and permanent. In the case of a wireless mobile hand held optical reader that communicates wirelessly with its individual base unit, this link can be made by programming the optical reader with information identifying the particular base unit so the optical reader directs its transmitted information to that base unit, or vice versa.
One prior art approach used for linking a wireless mobile hand held optical reader with an individual base unit is disclosed in U.S. Pat. No. 6,149,063 to Reynolds et al. In this approach, each base unit is assigned a unique bar code symbol that is scanned by the hand held optical reader to obtain information about the base unit to enable communication between the reader and the base unit.
Another prior art approach used for linking a wireless mobile hand held optical reader with an individual base unit is also discussed in U.S. Pat. No. 6,149,063 to Reynolds et al. In this approach, the hand held optical reader is physically inserted into a base unit. The hand held optical reader and base unit then exchange information via physical mating electrical connections to enable communications between the two devices.
While each of these prior art linking approaches increase the flexibility of the hand held optical reader systems over systems where the optical reader is permanently linked with a base unit, these approaches still have several disadvantages which limit the flexibility of the hand held optical reader to be used as an input device. For example, approaches where the hand held optical reader must scan optical indicia to obtain information about a base unit or other device requires each device to be linked to have unique optical indicia that can be read and understood by the optical reader. The approach whereby the hand held optical reader is linked using only the mating electrical connectors of the optical reader and base unit does not allow for confirmation that the radios in the devices are communicating or for linking between the hand held optical reader and other wireless devices that do not have mating electrical connectors.